[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 78.617818][ T30] audit: type=1800 audit(1570827230.661:25): pid=11353 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 78.641160][ T30] audit: type=1800 audit(1570827230.681:26): pid=11353 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 78.687863][ T30] audit: type=1800 audit(1570827230.711:27): pid=11353 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.55' (ECDSA) to the list of known hosts. 2019/10/11 20:54:05 fuzzer started 2019/10/11 20:54:09 dialing manager at 10.128.0.26:46157 2019/10/11 20:54:10 syscalls: 2412 2019/10/11 20:54:10 code coverage: enabled 2019/10/11 20:54:10 comparison tracing: CONFIG_KCOV_ENABLE_COMPARISONS is not enabled 2019/10/11 20:54:10 extra coverage: enabled 2019/10/11 20:54:10 setuid sandbox: enabled 2019/10/11 20:54:10 namespace sandbox: enabled 2019/10/11 20:54:10 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/11 20:54:10 fault injection: enabled 2019/10/11 20:54:10 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/11 20:54:10 net packet injection: enabled 2019/10/11 20:54:10 net device setup: enabled 2019/10/11 20:54:10 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 252.412691][ C0] ===================================================== [ 252.420962][ C0] BUG: KMSAN: use-after-free in kfree_skb+0x473/0x4c0 [ 252.427771][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc2+ #0 [ 252.435309][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 252.445389][ C0] Call Trace: [ 252.448699][ C0] dump_stack+0x191/0x1f0 [ 252.453099][ C0] kmsan_report+0x14c/0x2c0 [ 252.457590][ C0] __msan_warning+0x73/0xe0 [ 252.462083][ C0] kmem_cache_free+0x3df/0x2b70 [ 252.467003][ C0] ? kmsan_internal_set_origin+0x6a/0xb0 [ 252.472701][ C0] ? kfree_skb+0x473/0x4c0 [ 252.477161][ C0] ? kmsan_internal_unpoison_shadow+0x42/0x80 [ 252.483600][ C0] kfree_skb+0x473/0x4c0 [ 252.488096][ C0] ? packet_rcv_spkt+0x68d/0x7c0 [ 252.493307][ C0] packet_rcv_spkt+0x68d/0x7c0 [ 252.498071][ C0] ? packet_rcv+0x2110/0x2110 [ 252.502740][ C0] __netif_receive_skb_core+0x3aed/0x51a0 [ 252.508465][ C0] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 252.514349][ C0] netif_receive_skb_internal+0x3cc/0xc20 [ 252.520057][ C0] napi_gro_receive+0x67f/0xbb0 [ 252.525020][ C0] receive_buf+0x653b/0x8810 [ 252.529644][ C0] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 252.535587][ C0] virtnet_poll+0x666/0x1a10 [ 252.540407][ C0] ? refill_work+0x470/0x470 [ 252.545053][ C0] net_rx_action+0x7a6/0x1aa0 [ 252.549737][ C0] ? net_tx_action+0xc40/0xc40 [ 252.554492][ C0] __do_softirq+0x4a1/0x83a [ 252.559072][ C0] ? ksoftirqd_should_run+0x30/0x30 [ 252.564257][ C0] ? takeover_tasklets+0x900/0x900 [ 252.569440][ C0] run_ksoftirqd+0x25/0x40 [ 252.573877][ C0] smpboot_thread_fn+0x4a3/0x990 [ 252.579176][ C0] kthread+0x4b5/0x4f0 [ 252.583403][ C0] ? cpu_report_death+0x190/0x190 [ 252.588412][ C0] ? kthread_blkcg+0xf0/0xf0 [ 252.593004][ C0] ret_from_fork+0x35/0x40 [ 252.597399][ C0] [ 252.599707][ C0] Uninit was stored to memory at: [ 252.604827][ C0] kmsan_internal_chain_origin+0xbd/0x170 [ 252.610536][ C0] __msan_chain_origin+0x6b/0xe0 [ 252.615641][ C0] ___slab_alloc+0x1dbc/0x1fb0 [ 252.620401][ C0] kmem_cache_alloc+0xade/0xd10 [ 252.625234][ C0] skb_clone+0x326/0x5d0 [ 252.629461][ C0] packet_rcv_spkt+0x23f/0x7c0 [ 252.634208][ C0] __netif_receive_skb_core+0x3aed/0x51a0 [ 252.639948][ C0] netif_receive_skb_internal+0x3cc/0xc20 [ 252.645752][ C0] napi_gro_receive+0x67f/0xbb0 [ 252.650700][ C0] receive_buf+0x653b/0x8810 [ 252.655407][ C0] virtnet_poll+0x666/0x1a10 [ 252.660595][ C0] net_rx_action+0x7a6/0x1aa0 [ 252.665253][ C0] __do_softirq+0x4a1/0x83a [ 252.669892][ C0] run_ksoftirqd+0x25/0x40 [ 252.674322][ C0] smpboot_thread_fn+0x4a3/0x990 [ 252.679452][ C0] kthread+0x4b5/0x4f0 [ 252.683530][ C0] ret_from_fork+0x35/0x40 [ 252.687990][ C0] [ 252.690407][ C0] Uninit was created at: [ 252.694771][ C0] kmsan_internal_poison_shadow+0x60/0x120 [ 252.700578][ C0] kmsan_slab_free+0x8d/0x100 [ 252.705253][ C0] kmem_cache_free_bulk+0x3ad9/0x3f10 [ 252.710605][ C0] __kfree_skb_flush+0xb0/0x100 [ 252.715530][ C0] net_rx_action+0x1a5e/0x1aa0 [ 252.720272][ C0] __do_softirq+0x4a1/0x83a [ 252.724770][ C0] run_ksoftirqd+0x25/0x40 [ 252.729180][ C0] smpboot_thread_fn+0x4a3/0x990 [ 252.734112][ C0] kthread+0x4b5/0x4f0 [ 252.738198][ C0] ret_from_fork+0x35/0x40 [ 252.742585][ C0] ===================================================== [ 252.749495][ C0] Disabling lock debugging due to kernel taint [ 252.755634][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 252.762203][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Tainted: G B 5.4.0-rc2+ #0 [ 252.770856][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 252.780888][ C0] Call Trace: [ 252.784164][ C0] dump_stack+0x191/0x1f0 [ 252.788477][ C0] panic+0x3c9/0xc1e [ 252.792367][ C0] kmsan_report+0x2b4/0x2c0 [ 252.796862][ C0] __msan_warning+0x73/0xe0 [ 252.801343][ C0] kmem_cache_free+0x3df/0x2b70 [ 252.806268][ C0] ? kmsan_internal_set_origin+0x6a/0xb0 [ 252.811884][ C0] ? kfree_skb+0x473/0x4c0 [ 252.816290][ C0] ? kmsan_internal_unpoison_shadow+0x42/0x80 [ 252.822447][ C0] kfree_skb+0x473/0x4c0 [ 252.826670][ C0] ? packet_rcv_spkt+0x68d/0x7c0 [ 252.831600][ C0] packet_rcv_spkt+0x68d/0x7c0 [ 252.836347][ C0] ? packet_rcv+0x2110/0x2110 [ 252.841014][ C0] __netif_receive_skb_core+0x3aed/0x51a0 [ 252.846737][ C0] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 252.852611][ C0] netif_receive_skb_internal+0x3cc/0xc20 [ 252.858320][ C0] napi_gro_receive+0x67f/0xbb0 [ 252.863160][ C0] receive_buf+0x653b/0x8810 [ 252.868210][ C0] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 252.874087][ C0] virtnet_poll+0x666/0x1a10 [ 252.878684][ C0] ? refill_work+0x470/0x470 [ 252.883276][ C0] net_rx_action+0x7a6/0x1aa0 [ 252.887940][ C0] ? net_tx_action+0xc40/0xc40 [ 252.892683][ C0] __do_softirq+0x4a1/0x83a [ 252.897174][ C0] ? ksoftirqd_should_run+0x30/0x30 [ 252.902348][ C0] ? takeover_tasklets+0x900/0x900 [ 252.907443][ C0] run_ksoftirqd+0x25/0x40 [ 252.911847][ C0] smpboot_thread_fn+0x4a3/0x990 [ 252.916772][ C0] kthread+0x4b5/0x4f0 [ 252.920839][ C0] ? cpu_report_death+0x190/0x190 [ 252.925844][ C0] ? kthread_blkcg+0xf0/0xf0 [ 252.930415][ C0] ret_from_fork+0x35/0x40 [ 252.936283][ C0] Kernel Offset: disabled [ 252.940617][ C0] Rebooting in 86400 seconds..